[5] DIRECT advocated developing a single, high-commonality family of rockets named Jupiter, adapted closely from existing Space Shuttle systems.

[citation needed] Many configurations of Jupiter were seen as possible, but the DIRECT version 3.0 proposal, released in May 2009, recommended two: the Jupiter-130 and Jupiter-246, with claimed lift capacities exceeding 70 and 110 tonnes, respectively, to low Earth orbit.

[12][13][14][15] NASA's Exploration Systems Architecture Study (ESAS) of 2005 included a similar design to the DIRECT proposal using three Space Shuttle Main Engines (SSME).

Known as LV-24 in crew launch form, and LV-25 in cargo configuration, the idea was dismissed because it did not have sufficient performance for the proposed lunar program - however the concept was not considered using an Earth departure stage (EDS).

DIRECT took the final ESAS recommendation of using the EDS during the ascent phase of the flight to gain additional launch performance on the Cargo LV, and applied this same methodology to the LV-24/25.

Additional performance for carrying payloads to Low Earth Orbit would be provided by upgrading the main engines with Regenerative Cooling Nozzles to improve their efficiency.

[citation needed] The v1.0 proposal was submitted on October 25, 2006, to NASA's administrator, Michael D. Griffin, and a wide range of industry, political and advocacy groups involved in the Constellation program.

[citation needed] In late 2006, the head of the ESAS Study, Dr. Doug Stanley, declared that the DIRECT v1.0 proposal could not work as it relied on overly optimistic and speculative performance specifications for an upgraded RS-68 Regen engine.

[citation needed] According to the proposal, the single-stage Jupiter-120 could achieve low Earth orbit with two standard ablative RS-68 engines, while an extra RS-68 was required on the core stage of the heavier two-stage Jupiter-232.

[18] "DIRECT v2.0 falls significantly short of the lunar lander performance requirement for exploration missions as specifically outlined in Constellation Program ground rules.

Even more importantly, the Ares approach offers a much greater margin of crew safety - paramount to every mission NASA puts into space."

[25] The engine change was due to concerns that the ablatively-cooled RS-68 would not survive the intense heat produced by the nearby exhaust plumes of the Space Shuttle SRBs.

In May 2009 the Office of Science and Technology Policy announced the Review of United States Human Space Flight Plans Committee to be chaired by Norman R.

[26] On 17 June 2009, team member Stephen Metschan presented the DIRECT v3.0 concept to the committee, which was formed to offer independent advice to the incoming Obama Administration.

The original intent in the Exploration Systems Architecture Study (ESAS) Report was to have a crewed flight as early as mid-2011 after the Space Shuttle retirement in 2010.

In 2008, Lockheed Martin requested that NASA redesign Ares I in order to end integration risks with the Orion crew capsule.

DIRECT's proposal for a single launch vehicle were intended to remove the program risks associated with the possible cancellation of the Ares V launcher due to budgetary constraints.

The group suggested that the money saved on Ares V be reused to speed development work of such other elements as the Orion, the Jupiter-130, launch facility modifications and all associated systems.

Advocates said the DIRECT proposal would allow NASA to provide sufficient money to continue funding programs beyond launch vehicle development and operation, including extending its participation in the International Space Station, which was scheduled to end in 2016 as of 2009.

In contrast to these claims, NASA senior manager for the STS program, John Shannon stated that he thought the DIRECT proposal underestimated the costs for the Jupiter rocket family.

The DIRECT v3.0 JUS had a putative mass of 11.3 t for a propellant capacity of 175.5 t. While claiming a design heritage from the Centaur series of upper stages, DIRECT specifically cited new materials, new welding techniques, and a common bulkhead separating the Liquid Oxygen and Liquid Hydrogen tanks as sufficient to account for the low stage mass.

Initial launches would rotate crews and bring cargo to the International Space Station, a function carried out by Soyuz rockets at the time.

Launched with a partial upper stage propellant load of 75 t, a Jupiter-246 could deliver over 84 t of crew and cargo to a circular 241 km (130 nmi), 29° inclined orbit.

[citation needed] One of the primary goals of the DIRECT proposal is to develop a new heavy lift rocket in a shorter time frame.

[citation needed] DIRECT envisioned continued development and operation of NASA's Orion crewed spacecraft, including its Launch Abort System (LAS).

[citation needed] For crewed flights to the International Space Station (ISS), DIRECT said the added lift capacity of the Jupiter would allow significant cargo to be carried in a separate module mounted below the Orion spacecraft.

[citation needed] The DIRECT Team cited a number of particular features that were claimed to make a Jupiter-130 safer than the Ares I: The Jupiter design would re-use the proven method of Space Shuttle of attaching the SRBs to the tankage though an internal structural member.

DIRECT says this would avoid the inducing of potentially severe vibration in the vehicle, resulting from a "thrust oscillation" effect endemic in large solid rockets.

[citation needed] The envisioned lift capacity of the Jupiter-130 could allow protective hardware to be mounted inside the payload fairing, below the Orion spacecraft.

DIRECT postulated mounting a lightweight shield made from boron carbide and Kevlar between the spacecraft and the stages below to help protect the crew from shrapnel and other debris from a vehicle explosion.