 Mockup of Lynx spaceplane | |
| Function | Crewed suborbital launch and reentry |
|---|---|
| Manufacturer | XCOR Aerospace |
| Size | |
| Stages | 1 |
| First stage | |
| Engines | 4 |
| Thrust | 13 kN (2,900 lbf) |
| Propellant | LOX-kerosene |
TheXCOR Lynx was a proposedsuborbitalhorizontal-takeoff, horizontal-landing (HTHL),rocket-poweredspaceplane that was under development by the California-based companyXCOR Aerospace to compete in the emerging suborbital spaceflight market. The Lynx was intended to carry one pilot, a ticketed passenger, and/or a payload above 100 kilometres (62 mi) altitude. The concept has been under development since 2003 when a two-person suborbital spaceplane was announced under the name Xerus.
In January 2016, XCOR changed plans for the first flight of the Lynx spaceplane. It was initially planned for the second quarter of 2016 from theMidland spaceport in Texas,[1] but, in early 2016, it was pushed to an "undisclosed and tentative" date at theMojave spaceport.[2]
In May 2016,[3] XCOR announced development of the Lynx had been halted with layoffs of approximately one-third of the staff; the company intended to concentrate on development of their liquid hydrogen rocket under contract withUnited Launch Alliance, instead.[4]
Following the bankruptcy of XCOR Aerospace in 2017, the assets of the company were sold to the nonprofit organization Build A Plane, which will focus on education rather than suborbital flight.[5]
In 2003, XCOR proposed theXerus (pronunciation: zEr'us)suborbital spaceplane concept. It was to be capable of transporting one pilot and one passenger as well as somescience experiments. It would even be capable of carrying anupper stage which would launch nearapogee and, therefore, would potentially be able to carrysatellites intolow Earth orbit.[6] As late as 2007, XCOR continued to refer to their future two-person spaceplane concept asXerus.[7]
The Lynx spaceplane was initially announced in March 2008, with plans for an operational vehicle within two years.[8] In December 2008, a ticket price ofUS$95,000 (equivalent toUS$138,741 in 2024) per seat was announced, with flights intended to commence in 2010.[9] The build of the Lynx Mark Iflight article did not commence until mid-2013 and XCOR claimed that the first flight would take place in 2015.[10][11] In July 2015, ticket prices increased by 50% toUS$150,000 (equivalent toUS$198,982 in 2024).[12] In November 2015, three co-founders left their existing positions with the company to start Agile Aero. Dan DeLong (Chief Engineer) and Aleta Jackson left the company entirely, whileJeff Greason, the former CEO, remained on the Board of Directors until he resigned in March 2016.[13] Greason cited problems with the Lynx vehicle body, although the engine had been a success. As of mid-2016, development was suspended in favor of a ULA-contracted hydrolox engine, the 8H21.[4]
Passengers who had hoped to make flights in the Lynx included the winners from theAxe Apollo Space Academy contest and Justin Dowd of Worcester, Massachusetts, the winner of another contest called the Race for Space.[14]Metro International's Race for Space newspaper contest.[15] By July 2015, the passenger ticket was projected to costUS$150,000.[16]As of December 2015,Kayak.com was reportedly selling tickets for flights on the XCOR Lynx starting in 2016.[17]
In May 2016, the company halted development of the Lynx spaceplane and pivoted company focus toward development of itsLOX/LH2 engine technology, particularly on a funded project forUnited Launch Alliance. The companylaid off more than 20 people of the 50–60 persons on board before May.[4]
The Lynx was intended to have four liquid rocket engines at the rear of thefuselage burning a mixture ofLOX-Kerosene, each engine producing 2,900 pounds-force (13,000 N) of thrust.[18]
The Lynx Mark III was intended to be the same vehicle as the Mark II with an External Dorsal Mounted Pod of 650 kg (1,430 lb) and was to be large enough to hold a two-stage carrier to launch amicrosatellite or multiplenanosatellites intolow Earth orbit.[26]
The XR-5K18 is apiston pump fed LOX/Kerosene engine using a closed-loopbrayton cycle[26],[27] with 13 kN (2,900 lbf) of thrust.
The development program of the XCOR Lynx 5K18LOX/kerosene engine reached a major milestone in March 2011. Integrated test firings of the engine/nozzle combination demonstrated the ability of the aluminum nozzle to withstand the high temperatures of rocket-engine exhaust.[28]
In March 2011,United Launch Alliance (ULA) announced they had entered into a joint-development contract with XCOR for a flight-ready, 25,000 to 30,000 pounds-force (110,000–130,000 N) cryogenicLH2/LOXupper-stage rocket engine (seeXCOR/ULA liquid-hydrogen, upper-stage engine development project). The Lynx 5K18 effort to develop a newaluminum alloy engine nozzle using new manufacturing techniques would remove several hundred pounds of weight from the large engine leading to significantly lower-cost and more-capable commercial andUS government space flights.[29]
It was reported in 2010 that the Mark Iairframe could use acarbon/epoxy estercomposite, and the Mark II acarbon/cyanate with anickel alloy for the nose and leading-edgethermal protection.[30]
Theflight article Lynx Mark I was claimed as having been fabricated and assembled inMojave beginning in mid-2013.[31] The cockpit of the Lynx (made of carbon fiber and designed byAdamWorks, Colorado) was reported as being one of the items that held up the assembly.[19]
At the start of October 2014, the cockpit was attached to the fuselage.[32] The rear carry-through spar was attached to the fuselage shortly after Thanksgiving 2014.[33] At the beginning of May 2015, the strakes were attached to the airframe.[34] The last major component, the wings, were expected to be delivered in late 2015.[35] In January 2016, XCOR's CEO Jay Gibson said "…we anticipate the wings to be there in the very near future…" and the CTO Michael Valant said they were finding that calibrating the flaps was a challenge.[2] In February 2016, the first prototype was described as a "wingless shell."[36]
In XCOR's November 2016 news report, they stated that "Even though the program made great forward progress integrating the vehicle structural elements during 2015 and early 2016 the progress on the control surface elements lagged in design. To prevent potential rework resulting from implementing designs not yet mature the Lynx fabrication was paused, so our engineering team has gone back to the design board."[37]
Tests of the XR-5K18 main engine began in 2008.[38]
In February 2011, it was reported that engine tests were largely complete[23] and the vehicle aerodynamic design had completed two rounds of wind tunnel testing. A third and final round of tests was completed in late 2011 using a "1/60-scale supersonic wind tunnel model of Lynx."[20][23]
In October 2014, XCOR claimed that flight tests of the Mark I prototype would start in 2015.[10][11][39] By January 2016, however, technical hurdles led the company to state that they had not assigned a new projected date for test flights.[2]
In March 2011, XCOR submitted the Lynx as a reusable launch vehicle for carrying research payloads in response toNASA's suborbital reusable launch vehicle (sRLV) solicitation, which is a part of NASA's Flight Opportunities Program.[40] No contract for providing this was ever announced.
According to XCOR, the Lynx was intended to fly four or more times a day and would have also had the capacity to deliver payloads into space. The Lynx Mark I prototype was expected to perform its first test flight in 2015,[11][41] followed by a flight of the Mark II production model twelve to eighteen months afterward.[11]
XCOR had planned to have the Lynx's initial flights at theMojave Air and Spaceport inMojave, California[42] or any licensed spaceport with a 2,400-metre (7,900 ft) runway. Media reports in 2014 anticipated that, by the end of 2015 or in 2016, the Lynx was expected to begin flying suborbitalspace tourism flights and scientific research missions from a newspaceport on theCaribbean island ofCuraçao.[43][44] However, the company stated in January 2016 that they had not assigned a new projected date for test flights and a date for the launch of commercial operations could not be anticipated.[2]
Because it lacked any propulsion system other than its rocket engines, the Lynx would have to be towed to the end of the runway. Once positioned on the runway, the pilot would have ignited the four rocket engines, take off, and begin a steep climb. The engines will be shut off at approximately 138,000 feet (42 km) andMach 2. Thespaceplane would then continue to climb, unpowered until it reached anapogee of approximately 200,000 feet (61 km). The spacecraft would have experienced a little over four minutes of weightlessness before re-entering the Earth'satmosphere. The occupants of the Lynx were intended to have experienced up to four times normal gravity during re-entry. After re-entry, the Lynx would have glided down and performed an unpowered landing. The total flight time was projected to last about 30 minutes.[26] The Lynx was expected to be able to perform 40 flights before maintenance was required.
Orbital Outfitters was reportedly designingpressure suits for XCOR use.[45] In 2012, Orbital Outfitters reported that they had completed a technical mockup of the Lynx craft itself.[46]
In 2008, Mark I production was projected to costUS$10 million (equivalent toUS$15 million in 2024),[47][48] and the Mark II aroundUS$12 million (equivalent toUS$18 million in 2024).[49]