DeepFlight Challenger is a one-person personal submarine deep submergence vehicle with full ocean depth capability. It is an "aero-submarine" which uses hydrodynamic forces to descend, as the sub has positive buoyancy, utilizing DeepFlight technology from Hawkes Ocean Technologies. The submarine is currently owned by Virgin Oceanic.
The submarine was designed by Graham Hawkes and Hawkes Ocean Technologies. It was originally ordered by Steve Fossett for an attempt on the Challenger Deep, to become the first solo dive there. Planning for the submarine started in 2000. It was put on the ordersheet in 2005, with a depth capability of 37,000 ft. The craft was named "Challenger" after the Challenger Deep by Fossett. At the time of the order, this would have doubled the depth that a single-place sub would be capable of going. It was to have been a "secret project" of Fossett's to be the first to solo the Challenger Deep, and was secret at the time of his death in 2007. The project was put on hold when Fossett died, and locked up in a warehouse at Hawkes Ocean Technologies, by the then owners, Fossett's estate, but was later revived when Chris Welsh of Deep Sub LLC bought the unfinished sub and restarted the program in 2010. Welsh had purchased the sub and the Cheyenne yacht from the Fossett estate for around $1 million. Virgin Oceanic came in as sponsors a year later in 2011. At the time of Fossett's death, the sub had been almost finished, only four weeks from dive tests  and delivery.
Had the sub been finished as scheduled, it would have been the first to return a solo manned mission to the Challenger Deep.
The submarine uses composite technology to create a lightweight sub with great depth capabilities. The viewdome is made from quartz, while the rest of the pressure hull uses carbon/epoxy composites. The interface between dome and hull is by bonded titanium rings. The sub has a 24hour endurance, 3kt bottom speed, and 350 ft/min dive rate. Without ballast attached, the sub is positively buoyant, it uses syntactic foam for buoyancy. The submarine does not have a temperature control system for the cabin, so will tend towards ambient temperature. The sub weighs 8000 lbs, and does not need a dedicated mothership. It has a 15 mi range, 6kt maximum speed, and 3-axis freedom of motion. It uses LED lighting instead of arc lights, and has a laser navigation system. The sub can dive to the bottom of the ocean and get back to the surface in 5 hours. The design draw from DeepFlight II, another Hawkes Ocean Technologies full depth submarine. The pressure hull is rated to withstand 20,000PSI (more than the 16,000PSI at the bottom of the Mariana Trench). The sub is smaller than James Cameron's Deepsea Challenger. Challenger represents the third generation of DeepFlight technology, one generation behind the DeepFlight Super Falcon.
- May 2007
- Penn State Applied Research Laboratory Building; Pressure test of the pressure hull to Mariana Trench like pressures. Passed test, except for a crack in the viewdome due to a manufacturing defect.
- November 2007
- cancelled tests, in the wake of Steve Fossett's death.
- February 2012
- Alameda Naval Air Station (Oakland, California, USA); Ballast system was tested. Submerged battery and engine testing, while manned.
Five Dives project
Richard Branson and Chris Welsh of Virgin Oceanic plan on using DeepFlight Challenger to reach the deepest point of each of the world's five oceans, the Mariana Trench of the Pacific Ocean (36,201 ft), the Puerto Rico Trench of the Atlantic Ocean (28,232 ft), the Diamantina Trench of the Indian Ocean (26,401 ft), South Sandwich Trench of the Southern Ocean (23,737 ft), and Molloy Deep of the Arctic Ocean (18,399 ft). The Cheyenne yacht will be used as the mothership for the dive efforts.
It is planned that Branson would pilot the sub to the Puerto Rico Trench, while Chris Welsh would pilot it for the Mariana Trench dive. Virgin Oceanic had hoped to be the first team to solo to the bottom of the Mariana Trench, and first team to return to the Challenger Deep since the Trieste left, however, James Cameron's Deepsea Challenge project beat them to it in March 2012. There has been an undeclared race on to return to the Challenger Deep between four teams, Cameron's, Virgin Oceanic's, Google-Schmidt/DOER's, and Triton Submarines'. The attempt on Challenger Deep had been announced in April 2011.
Based on testing at high pressure, the DeepFlight Challenger was determined to be suitable only for a single dive, not the repeated uses that had been planned as part of Virgin Oceanic service. As such, in 2014, Virgin Oceanic "scrapped" plans for the five dives project using the DeepFlight Challenger, as originally conceived, putting plans on hold until more suitable technologies are developed.
As of February 2012, several other vehicles are under development to reach the same depths. The groups developing them include:
- Deepsea Challenge, a program created by James Cameron and National Geographic, using the submarine Deepsea Challenger, that carries a crew of one, and which became the second manned vehicle to reach Challenger Deep.
- Triton Submarines, a Florida based company that designs and manufactures private submarines, whose vehicle, Triton 36000/3, will carry a crew of three to the seabed in 120 minutes.
- Deep Ocean Exploration and Research (DOER) Marine, a San Francisco Bay Area based marine technology company established in 1992, that is developing a vehicle, Deepsearch (and Ocean Explorer HOV Unlimited), with some support from Google's Eric Schmidt with which a crew of two or three will take 90 minutes to reach the seabed, as the program Deep Search.
- Virgin Oceanic, Sub (accessed 27 March 2012)
- CNet News, Steve Fossett's unfinished legacy: Deepest ocean exploration, Daniel Terdiman, 3 October 2008 (accessed 27 March 2012)
- New York Times, "The Challenger’s Deep-Sea Brethren", Andy Isaacson, 27 March 2012 (accessed 27 March 2012)
- Hawkes Ocean Technologies, Infosheet DeepFlight Challenger (accessed 27 March 2012)
- KGO-TV ABC 7, "Fossett's secret project was built in Richmond", Thursday 2 October 2008 (accessed 27 March 2012)
- Boing Boing, "Richard Branson launches Virgin Oceanic: deep-sea exploring submarines", Xeni Jardin, 5 April 2011 (accessed 27 March 2012)
- Los Angeles Times, "With spaceships and airplanes under his belt, Richard Branson turns to submarines", Mike Reicher and Kurt Streeter, 6 April 2011 (accessed 27 March 2012)
- Virgin Oceanic, Operations Team (accessed 27 March 2012)
- San Francisco Chronicle, "Winged sub almost ready to go very deep", Tom Stienstra, 12 October 2008 (accessed 27 March 2012)
- CBS News, "With Virgin Oceanic, Branson wants to go deep, really deep", 5 April 2011 (accessed 27 March 2012)
- CNN, "Super-light sub has 'capability greater than U.S. Navy'", Mairi Mackay, 11 September 2009 (accessed 27 March 2012)
- CNet News, "Cameron and Branson race to bring urgent attention to oceans", Daniel Terdiman, 26 March 2012 (accessed 27 March 2012)
- Composites World, "Deepsea submersible incorporates composite pressure capsule", Sara Black, 31 August 2010 (accessed 27 March 2012)
- Virgin Oceanic, Branson Answers Kids Questions, 2012 Jan 19 (accessed 27 March 2012)
- Hawkes Ocean Technologies, DeepFlight Challenger (accessed 27 March 2012)
- Hawkes Ocean Technologies, Ocean Everest (accessed 27 March 2012)
- Popular Mechanics, "Q&A With Graham Hawkes, the Man Who Built the Deep Flight Challenger Submersible", Sarah Fecht, 8 April 2011 (accessed 4/4/2012)
- Virgin Oceanic, Testing the Sub, 2012 Feb 21 (accessed 27 March 2012)
- CNet News, With Virgin Oceanic, Branson plans to get deep, Daniel Terdiman, 5 April 2011 (accessed 27 March 2012)
- CNet News, "DeepFlight Challenger", 5 April 2011 (accessed 27 March 2012)
- The Register, "Richard Branson to prowl oceans' hadal depths in flying sub", Lester Haines, 6 April 2011 (accessed 27 March 2012)
- Macleans' Magazine, "James Cameron’s giant dive for mankind", Kate Lunau, 22 March 2012 (accessed 27 March 2012)
- Mendick, Robert; Nicholls, Dominic (13 Dec 2014). "Sir Richard Branson quietly shelves Virgin submarine plan". The Telegraph. Retrieved 15 Dec 2014.
- BBC News, "Race to the bottom of the ocea", 22 February 2012 (accessed 27 March 2012)
- National Geographic, "James Cameron Completes Record-Breaking Mariana Trench Dive", Ker Than, 25 March 2012 (accessed 27 March 2012)
- BBC News, "Race to the bottom of the ocean: Cameron", 8 March 2012 (accessed 27 March 2012)
- Triton Submarines, "Triton 36,000 Full Ocean Depth Submersible" (accessed 27 March 2012)
- BBC News, "Race to the bottom of the ocean: Triton", 22 February 2012 (accessed 27 March 2012)
- DOER Marine, "Deep Search" (accessed 27 March 2012)
- BBC News, "Race to the bottom of the ocean: DOER", 22 February 2012 (accessed 27 March 2012)
- BBC News, Race to the bottom of the ocean: Virgin, 22 February 2012 (accessed 27 March 2012)
- Virgin Oceanic, Sub
- Hawkes Ocean Technologies, DeepFlight Challenger
- CNet News, DeepFlight Challenger archive