One of These Aircraft is Not Like the Others

SpaceShipOne on the floor beside the Spirit of St. Louis of the National Air & Space Museum. (Credit: National Air & Space Museum)
SpaceShipOne on the floor beside the Spirit of St. Louis of the National Air & Space Museum. (Credit: National Air & Space Museum)

I posted this photo earlier from the National Air & Space Museum. And it got me thinking. Exactly what do these aircraft have in common? How do they differ?And what does this tell us about flight test and prizes?

So, I dug into things a bit. The results are in the table below.

Ryan NYP
Spirit of St. Louis

Bell X-1
Glamorous Glennis
SpaceShipOne
Manufacturer:Ryan Airlines
Bell AircraftScaled Composites
No. Built:231
First Flight:April 28, 1927Jan. 25, 1946May 20, 2003
 Final Flight:April 30, 1928May 12, 1950
 Oct. 4, 2004
No. of Flights:174 (Spirit of St. Louis)158 (83 X-1-1, 74 X-1-2, 1 X-1-3)14 (6 powered)
Total Flight Time:489h 28m (Spirit of St. Louis)?4h 11m 11s
Major Milestone:First solo trans-Atlantic crossingBroke sound barrier in level flightFirst private spaceflight
Date of Major Milestone:May 20-21, 1927Oct. 14, 1947June 21, 2004
Pilot for Major Milestone:Charles LindberghCharles YeagerMike Melvill
Seats:113
Top Speed:133 mph957 mph (Mach 1.26)2,170 mph (Mach 3.09)
Service Ceiling:16,400 ft71,902 ft367,360 ft
Wingspan: 46 ft28 ft 16 ft 5 in
Height:9 ft 10 in 10 ft8 ft 9.6 in
Length:27 ft 7 in30 ft 11 in 28 feet
Loaded Weight:2,888 lb12,225 lb7,920 lb
Power Plant:Wright Whirlwind J-5CReaction Motors XLR-11-RM3N2O/HTPB SpaceDev hybrid
Predecessor:1926 Ryan M-2NoneNone
Successor(s) & Variant(s):Ryan B-1 Brougham, Ryan B-7 Brougham, Ryan C-1 Brougham, Ryan B-1X BroughamX-1A, X-1B, X-1D, X-1E, X-2SpaceShipTwo
Awards Won:$25,000 Orteig PrizeCollier Trophy$10 million Ansari X Prize; Collier Trophy; Iven C. Kincheloe Award

The most striking figures in the table involve the differences in the number of flights and the flight time. The Spirit of St. Louis had a total of 174 flight before it was retired to the Smithsonian Institution lasting nearly 89.5 hours. Charles Lindbergh’s Orteig Prize-winning flight took 33 hours and 30 minutes out of that total. The aircraft was flown extensively before and after the historic flight from New York to Paris.

Interestingly, an exact copy of the Spirit of St. Louis was built for the Japanese newspaper Mainichi. It apparently had a short operational history. Wikipedia reports it set a number of records in 1928 before a crash put it out of commission for good.

The X-1-1 (Glamorous Glennis) flew 83 flights over four years of operations between 1945 and 1950. The second X-1 flew an additional 74 times, while the third one had a single glide flight before it was destroyed following a captive carry. We don’t have total flight times for the three aircraft.

By contrast, SpaceShipTwo had a mere 14 flights, with six of them being powered by the ship’s hybrid engine. Three of those flights made it into space by flying higher than the 100 km Karman line. The vehicle’s total flight time is just over 4 hours 11 minutes.

This is an extraordinarily short flight test program for an experimental vehicle. Scaled Composites had originally planned to fly it after its 14th flight, which won the $10 million Ansari X Prize.  However, financial backer Paul Allen decided ; he decided to ship the spacecraft to the National Air & Space Museum. He was worried that if SpaceShipOne kept flying, someone could get hurt.

The decision to end testing of SpaceShipOne after only six powered flights ended up limiting its value its successor, SpaceShipTwo. Scaled really needed a lot more flights to understand the propulsion system, how the vehicle’s composite structure held up to flight stresses, and a number of other issues.

The Spirit of St. Louis is the only aircraft of the three to have a predecessor, the 1926 Ryan M-2 mail plane. In order to extend the aircraft’s range to 4,000 miles, the wingspan was extended 10 feet and additional changes were made. The aircraft had a number of successors.

SpaceShipOne had the biggest leap to its successor. It was a small three-seat vehicle roughly the size of the X-1.  SpaceShipTwo is three times larger, with room for two pilots and six passengers in the back. Engineers have had a difficult time scaling up the hybrid engine for the larger vehicle.

The X-1’s successors included the X-1A, X-1B, X-1D, X-1E and X-2. The X-1E was the rebuilt second X-1 aircraft, which was retired in 1951. The X-1E completed 26 flights between 1955 and 1958.