Study reveals a six RS-68 and 5.5 segment booster for Ares V

The mammoth Ares V is continuing to grow – on paper at least – to olympic proportions to close the performance shortfall in the Ares architecture.The new vehicle – that is officially classed as a study option, but touted as the new baseline – shows an Ares V with two stretched 5.5 segment Solid Rocket Boosters, an even longer Core Stage powered, now by six RS-68 main engines, and a 10 meter diameter Upper Stage and matching Payload Fairing.

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All of this article is based on documented L2 information. For an overview of how L2 works, **click here for sample video**

**ARES I LIVE UPDATE PAGES**

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Ares V.5: 

Ares V will be the required workhorse providing Constellation with the ability to leave Low Earth Orbit (LEO) in their exploration architecture.

The previous Ares V baseline was a 10 meter core, powered by 5 RS-68 engines from the Delta IV vehicle – flanked by two 5.0 segment Solid Rocket Boosters as to be used on the Ares I’s First Stage. The J-2X powered Upper Stage had already changed from 8.4 meters in diameter to a 10 meter stage, flush with the Core Stage.

However, the earlier Ares-V configuration has been suffering from an inability to close the performance requirements for being able to heavy lift the four-man Altair Lunar Lander being planned. With Ares I lifting the Orion spacecraft, the Ares-V needs to push 75.1 mT of payload through Trans-Lunar Injection (TLI) but was only able to push 64.6 mT.

This new more powerful configuration, identified as the ‘LV 51.00.48’ is now able to put 71.1 mT through TLI. While this configuration still can not reach its targets, this is a clear improvement towards closing the performance requirements NASA has for the Lunar architecture.

Each new reusable 5.5 segment SRB, will contain over 1.5 million pounds of propellant which will produce a peak of 3,774,000 million lbs of thrust and will have a vacuum Isp of 275.5 seconds. The 38 percent larger SRB’s will burn for 116 seconds – a full 8 seconds shorter burn time than Space Shuttle – before being jettisoned.

They feature a new ‘333-07 Trace’ PBAN solid propellant mix derived from that currently used by the Shuttle, although there is still the option to go to a new HTPB mix if the trade studies are favorable.

To accommodate the new lengthened boosters, the Liquid Hydrogen Tank on the Core Stage has been stretched by 190.3”. Together with a proportional stretch to the Liquid Oxygen Tank this growth puts the new baseline vehicle at 381.1 ft tall – nearly 20 feet taller than the old baseline.

To save weight, this version of Ares V assumes all non-pressurized structures on the Core Stage will be built out of new IM7 composite materials instead of more traditional Aluminum-Lithium alloy.

The 6 RS-68 engines powering the Core will fly at 108 percent power levels (6 percent higher than used on Delta-IV currently) and will each produce 702,055 lbs of thrust and have an Isp of 365 seconds at sea level and will have 797,000 lb of thrust and will have an Isp of 414 seconds in a vacuum.

Total expected burn time for the Core will be 303 seconds and the 6 main engines will produce a maximum of 4.17G during the launch. The EDS will likewise be constructed out of mostly composite materials.

The J-2X engine will burn at the 100 percent power level for the orbital insertion burn, but will burn at the 81 percent power level for TLI. The reduced thrust optimizes the Isp for the mass-critical TLI burn. The insertion altitude has been raised from 120 nmi to 131.5 nmi circular.

Total roll out weight with the crawler and the MLP (Mobile Launch Platform) will be approximately 18 million lbs, which exceeds the capability of the existing crawlerway rated for 16.8 million lbs. The ability for Ares V to remain within its budget targets is now considered a 4×4 risk on the standard 5×5 risk matrix.

Ares I Preliminary Design Review (PDR) Latest: 

Meanwhile, news from the Ares I PDR shows the Mobile Launcher (ML) will have to be tweaked, as a new drift analysis shows that the vehicle – or its plume – could impact the tower during climbout. Engineers have also been able to shorten the first stage by 8 inches at the instrumentation bay. 

The currently favored mitigation approaches – still undergoing a trade study – for thrust oscillation will add around 500 lbs to Orion for shock mounting on the crew seats and vital components. Thrust oscillation is now categorized as a 5×4 risk for the upper stage. 

The Loss of Mission (LOM) probability is calculated at 1:441, and the Loss of Crew (LOC) at 1:1563. The target for LOM is 1:500, and the minimum for LOC is 1:1000 with a goal of 1:2000. 

Constellation will also aim to shift to SI metric measurements after PDR. The ISS variant of Ares I is designated as a ‘transition’ vehicle, with major systems in metric and smaller subsystems in Imperial.

The goal is for lunar missions to ‘fly metric.’ However, such an undertaken may be shot down by associated cost risks to the program.

This article is part 6 of a new series of Ares/Orion articles based on documentated engineering processes being carried out on the vehicles at this time. Click for: **Part 1** – **Part 2** – **Part 3** – **Part 4** **Part 5**

Selection of L2 Resources For Ares I, V and Constellation: 

Ares V (5.5/6xRS-68) Presentation. Orion Parachute Vehicle Images. Latest Risk Matrix for Ares. SI Unit Directive Document. CxP PMR08 Manifest. PDR and associated notes from CPCB meeting. Full (and very expansive) list of current Ares/Orion mass and status report. Ares I ‘Parasorber’ TO migitation hardware presentation and animation. Orion Parachute Test Vehicle (PTV) Photographs.  

110mb worth of Ares I-X Weekly Test Presentations (Ares I-X, J2-X etc. up to end of April) The Orion LIDS (Low Impact Docking System) Section (Images, Videos, Engineering Notes). Hi Res Images of Ares I in the VAB. Ares I-X Integrated Milestone Charts. Ares I Thrust Oscillation Focus Team Status Presentations (over 50mb – includes DTO on Shuttle missions), Ares I-X Global Buckling Status Presentation, Ares I – Launch Pad Stabilization and Damping Presentation, Ares I: Purge/Vent/Drain and Vehicle Access Presentation.

Ares Tilt Up Umbilical Arm (TUUA) Test – Video, Ares/Orion Comm and Tracking Presentation, Ares I Nozzle Extension Update Presentation, Ares/Orion Integrated Stack TIM Summary (Major Issues) Presentation, Orion Land vs Water Landing Update + Crew Survival (post 36 hrs) Presentations.

Altair Overview Presentation. Ares I Risks and Status. Ares I-X Booster Recovery Images and Video. Ares I-X Pad Images. Ares I-Y Mission Overview Video (50mb – Superb).  Orion Lunar Transit CGI Video. (Several more videos, including first video of Orion splashdown).