Setting the Spaceplane Stage

Dream Chaser shuttle. (Credit: NASA)

HAMPTON, Va. (NASA PR) — Fly frequently, travel safely, land on (most) runways, and operate economically: such are the guiding principles for 21st century spaceplanes, cargo-carrying aerospace workhorses routinely launching to low-Earth orbit for space station resupply and crew transfers. Fans disconsolate after retirement of NASA’s shuttle fleet can take heart: The next generation in reusable space vehicles is set to debut.

A new spaceplane stage has been set by decades of NASA work done at Langley Research Center on horizontal-landing, or HL, lifting bodies. Sporting a design reminiscent of the upward-flexing pectoral fins on breaching manta rays, HL vehicles feature rudimentary wings. As the craft settles through Earth’s atmosphere from orbit the chubby, cigar-like fuselage generates lift from more air pressure on the bottom than on the top.

Flying Wingless First championed for flight testing by NASA engineer H. Dale Reed in the early 1960s, the HL concept went through a number of design changes and improvements, eventually resulting in a series of experimental piloted aircraft. The Northrop HL-10 – referring to the tenth design evaluated by Langley engineers – was built to assess specific structural refinements. Langley laboratories and wind tunnels hosted a variety of early studies on scale models before any full-scale craft were constructed.

The HL-10 would be one of five “heavyweight” lifting body designs flown at NASA’s Flight Research Center (now known as Armstrong Research Center) from July 1966 to November 1975 to demonstrate a pilot’s ability to maneuver and safely land a wingless vehicle. The information the lifting-body program generated contributed to a database crucial to the genesis of the space shuttle program.

A New Kid Spurred by the Soviet Union’s development of its subscale, unmanned BOR-4 – a testbed for the country’s would-be Buran space shuttle – by the 1980s Langley had set to work on a HL-10 successor, known as the HL-20, or “Personal Launch System (PSL).” The effort’s goals were straightforward: to assess the feasibility of low operational costs, make improvements to flight safety, and evaluate the possibility of conventional-runway landings. Yoked to the PSL research was wind tunnel testing and human-performed landing scenarios created in Langley simulators.

Artist’s concept of an HL-20 at a space station. (Credit:: NASA)

By 1990s, a 29-foot full-size, non-flying HL-20 model was built by the students and faculty of North Carolina State University and North Carolina A & T University to study crew-seating arrangements, habitability, equipment layout and how best to enter and exit. Although never flight-tested, the PSL did ultimately deliver: its design would be the basis for development of Sierra Nevada’s Corporation’s (SNC) Dream Chaser.

Mission Flexibility In January 2016 SNC was one of three companies awarded contracts to ferry cargo from 2019 through 2024 to the International Space Station (ISS). Under the terms of NASA’s Commercial Crew Program, and as part of a Space Act Agreement, SNC is able to use agency wind tunnels for Dream Chaser studies and experiments. That’s where Langley came in, mounting a Dream Chaser scale model in its Unitary Plan Wind Tunnel for extensive aerodynamic data gathering, which was subsequently added to the spacecraft’s performance database.

The scale model of the Dream Chaser is readied for wind tunnel testing at high speeds that simulate the conditions it will encounter during its flight through the atmosphere returning from space. (Credit: NASA/David C. Bowen)

Although a quarter of the size of any of the now-retired space shuttles, Dream Chaser can carry as many as seven crew members. Although there is but one basic spacecraft airframe, there are two system variants optimized for either manned or unmanned missions. SNC asserts the Dream Chaser can be reused 15 or more times, more than any other current operational space vehicle. The company also touts the spacecraft’s flexibility in remote sensing, satellite servicing, and even “active debris removal,” otherwise known as space-trash cleanup.

A second round of Dream Chaser flight tests at NASA’s Armstrong Research Center is slated to continue through the end of the 2017 calendar year.

  • Mr Snarky Answer

    No one said D2 would be “converted”. I said it is a dead-end, because new vehicles will not use this approach.

  • Mr Snarky Answer

    More likely that the mini-BFR will supersede D2 for long term LEO access as well. No one said D2 was changing. It however has no development path beyond D2.

  • publiusr

    Falcon Heavy looks big enough to launch HL-42.

    I think OSP was to have been launched “sideways” with the D-IV Heavy strap-ons seeming above and below the spaceplane when viewed from above (on the pad)

    I always worried about pitch loads and bending moments for top mount spaceplanes

  • publiusr

    Yeah–but his wife’s dad is an Air Force man who could really ruin his day.

  • publiusr


    The Air Farce stole space from the ABMA

  • Tom Billings

    The Clinton administration is indeed slowly fading into the past. However, the portion of the Democratic Coalition they responded to were the growing pacifist/anti-military/fund academia with another “peace dividend” groups. When Clinton’s aides put together their WH “space architect” position, specifically to give a disinterested veneer to depriving *any* part of the military of crewed access to Space, they calmed that portion of their coalition. Those groups are still alive, awake, and well-funded.

    The consensus for defending US interests beyond the borders of the US began collapsing in 1965, and has not been repaired. As long as academia continues grinding out large numbers of graduates who believe their virtues are inherently greater than those who are in the military, this will continue.

    Given that any crewed military space plane can be a “multiplier” for a “Space Force”, that portion of the Democratic Coalition will want as little to do with it as the full “Space Force” concept itself. They foresee, possibly correctly, that even more than with Navies, when this was first spoken in the 16th century, “what is needed is money, money, and more money”. It certainly has been the case for the AF.

    Yes, a majority of those costs are the agency costs of Congress itself. Do not expect the Democrats to publicly acknowledge that enough to cut it down, or the Republicans. Both the legal and the technological basis for a “Space Force” will be fought, and fought tooth and nail, by those who view the money needed for it as already belonging, by right, to academia.

  • duheagle

    D2 is only a dead end anent Mars. As a “retail” people carrier, D2 should enjoy a long and productive life servicing LEO destinations, especially after it gets its legs back.

    Elon’s Mars plans always included “wholesale” people carriers. Even downsized, BFS will have a passenger payload at least an order of magnitude more than D2’s max. That makes BFS a poor fit for the job of moving small numbers of people to and from LEO.

    In freighter and tanker versions, BFS seems likely to be a common sight in LEO, but as a people carrier that would only be true if some entity builds something like Von Braun’s Wheel.

  • duheagle

    As noted previously, mini-BFS will be way oversize for most Earth-to-Leo-and-back crew hauls.

    D2’s lack of a development path is a non-issue. All the additional “development” it needs is getting its amputated legs back. D2 has a job to do and it is likely to be the low-cost way to do said job for a good long while.

    The wrenches and hammers in my toolbox have no “development paths” either. That hardly makes them either obsolete or useless.

  • duheagle

    I think the Air Force already used up all its “ruin NASA’s day” tickets on the Shuttle.

    More to the point, USAF seems to have warmed to SpaceX as much or more than has NASA.

    “Daddy, Daddy, he was looking at her ass!

    “I’ve seen her ass, Kitten. I don’t blame him. Maybe you ought to consider hitting the gym, eh?”

  • Mr Snarky Answer

    Your analysis is all wrong here, similar to it being wrong for sub-scale Raptor and sub-scale BFR before.

    You make some distinction between LEO transport and Mars transport that SpaceX and more specifically Musk doesn’t ever make. Originally, the Mars lander was going to be a follow on to D2 style capsule but much larger to provide human access to Mars, in the meantime D2 would be a LEO crew access and Mars for science/pathfinding. Hence, D2s operations would be leveraged to gain insight on the much larger vehicle. That is not the case and as of Sept last year (from public perspective only) he switched, making D2 a dead-end. This is in Musk’s own words in the video up thread. But these transportation systems are generic, LEO, Moon, Mars…

    Mini BFR / ITYs, once online and ready to go, will be much cheaper to operate as it will be a fully reusable launcher, non-hypergolic and easier to turn around than RP-1 based stages. It will also be a day one propulsive lander meaning the turnaround time on the spaceship will be much cheaper/faster.

    Regardless of how many people want to ride or mix or people and cargo F9/D2 will be obsolete by fully operational mini-BFR / ITYs. That is the whole point of the program. Now, this is going to take years, so D2 has a lovely honeymoon in front of it, but in the end, not economic compared to its planned replacement. So, dead end. If you don’t like this approach, take it up with Musk.

  • duheagle

    You seem to be coming at this from an entirely technical standpoint without consideration of the politics and economics in which the tech is embedded.

    I was wrong about subscale Raptor and down-sized BFR/BFS mainly because I missed some political changes and their economic consequences.

    It was less than a year ago that Elon outlined the erstwhile ITS architecture. Its scale was, I believe, based on Elon’s thinking at the time. This was, I think, in retrospect, that NASA could be persuaded, incrementally, over the next several years, to abandon its own increasingly untenable Mars plans and throw in with him on his own.

    That didn’t turn out to be the case. Instead, the old-line NASA defenders of empire and the “operations” types – of which NASA accumulated far too many during the Shuttle era – have elected to make a sort of last stand in defense of their accustomed privileges and perquisites by attempting to consequentially get in SpaceX’s way. The mechanism by which they apparently hoped to accomplish this was the sudden cultivation of a bureaucratic briar patch anent SpaceX’s longstanding plans to do propulsive landings with Dragon 2. At one stroke the NASA ancien regime could disadvantage D2 anent legacy contractor product Starliner and scupper Red Dragon.

    There are, I think, three events – two that have already occurred and one that is imminent – that combined to convince many of the NASA Old Reptiles that they had suddenly all but run out of time to try stopping the Sweet Meteor of Death – SpaceX – which threatens their extinction:

    1) The ITS presentation, itself. The Old Guard, I think were sure that Elon’s grandiose vision would dissolve in a gale of derisive laughter. Instead, the centroid of commentary quickly became that it was SpaceX which had the more credible Mars plan, not NASA.

    2) The announcement of the circum-lunar tourist excursion using two yet-to-be-flown items, Falcon Heavy and Dragon 2. The Old Guard had reluctantly accepted the ceding of LEO to private enterprise, but still thought of deep space as its own, permanent, bailiwick. Now with the Mars architecture announcement and then this cheeky Apollo 8 replay – well in advance of NASA’s own Apollo 8 replay with SLS and Orion – Musk and SpaceX were no longer these California weirdos who got lucky but an existential threat to The Established Way.

    3) The upcoming maiden flight of Falcon Heavy. Given the epic miscalculation about the public reaction to the ITS announcement, I think sudden fear stalked the halls of Houston and Huntsville that, once this thing had actually flown, too many Questions To Which There Are No Good Answers would be asked about SLS and Orion – a matter of existential threat to much of the NASA Old Guard.

    NASA had no real leverage over this project, which it neither paid for nor has any known plans to use for anything.

    The only thing of SpaceX’s that could be messed with on short notice was D2. Hence, the not-quite-a-ban-but-yeah-actually-a-ban on D2 propulsive landings. This had the added advantage of keeping Musk off Mars at least a bit longer than would otherwise likely have been the case.

    Musk, being the Gregory Hines/Bojangles-level genius tap dancer that he is, has, it seems, contrived to redraw the BFR/BFS so as to:

    a) fit within a budget SpaceX can cover entirely on its own dime over the next few years, and

    b) broaden BFR/BFS’s intended protfolio of uses from strictly Mars-centricity to LEO, cis-lunar and lunar applications as well.

    Item b) is the most important. It is, in effect, SpaceX’s plausibly deniable way of staking its own claim to all of deep space as an arena in which it expects to operate.

    Among the keys to this revised strategy is making maximum use of Falcon 9/FH/D2 as cash cows – even more so than they already are. That is incompatible with your apparent notion that SpaceX wants to pipe the entire lot down the road ASAP in order to replace them with BFR/BFS for every type of mission.

    I think D2 will get its legs back and do propulsive landings because I think a good market for such will exist a few years hence in crew rotations for private LEO platforms and, perhaps even more important, as a basis for a “Grey Dragon” oriented toward heavy-duty instrument hauling for deep space probe missions both scientific and commercial.

  • Mr Snarky Answer

    Mostly agree but the last paragraph is not going to happen. Shotwell and Musk both have stated once D2 and F9 block 5 are out the door they are going to into sustaining and resources moved to ITSy. They may do the work for a bigger fairing on FH and vertical integration in conjunction with USAF contracts (to pay for it) but that’s it. They are, as you say, revenue generators not platforms in active development. In the words of Top Gun, you are holding on to tight.

    Like D1 now, there will get to the point where they are just refurbishing them and not building new ones, just to optimize production resources for ITSy. Building 12-16 D2s with 3-5 reuses per hull gives them between 36 and 80 missions worth of hulls as a bridge to ITSy. As they fly, they can gauge where they are on this front and build D2s accordingly. D2 is just a bridge, the timeline for BFR is early 2020s. Once the full resources are freed up the development will move rather quickly. Even if human rated spaceship isn’t flying by 2022 who is going to sink money into D2 when SpaceX is flying the baseline booster and upper stage ITSy spacecraft will be built on?

  • duheagle

    We have, it would seem, reached an impasse.

    Part of our different perspectives seem to arise from what we each apparently consider to fall within the borders of “sustaining” and “development,” respectively. I view D2 as, essentially, fully developed now. Because of NASA’s edict anent propulsive landings, D2 is – as I see it – in the near-term process of being de-developed a bit. This is a process whose later reversal fits well within what I would view as “sustaining” engineering effort. I see the same as being true for the relatively minor tweaks needed to build “Grey Dragons” once D2 gets its legs back.

    I have no idea how many reuses a D2 will be good for, but I’m quite sure the number is far higher for a D2 that lands propulsively than for one which has to be repeatedly subjected to dunking in sea water. The shorter potential production run and the elimination of all the time and expense associated with wringing each D2 dry after its dip in the ocean would almost certainly more than cover whatever it would take to put the legs back on.

    I don’t say your scenario has zero probability of coming to pass, I just don’t see either a technical or economic rationale for it.

    That said, the proof of the pudding will ultimately be in the eating. If both of us are still around even three years hence, it seems quite likely the “pudding” will, by that time, be well-specified as to flavor and nutritional specifications and we will simply be waiting for it to finish cooking and cooling.

  • Jeff2Space

    DOD budgets aren’t even in the same “bucket” as budgets for “academia”. That and the US spends more on “defense” than any other country. In fact, the US spends more than the next 10 or so highest spending countries *combined*.

    I think you post has gone off into lala land.

  • Tom Billings

    The comparison with other countries is irrelevant to US internal budgets.

    The comparison between the military and academia is done by academia and its partisans in Congress.

    The defense budget is *always* the first thing that academic progressives want to cut when told that money for their cause of the decade (whatever decade it happens to be) isn’t available.

    Of course they aren’t in the same congressional budget “bucket”, but that makes no difference to the pacifist part of the progressive coalition. They just want the money. They believe that opposing military activity in Space is one way to get it. So they oppose that.