Space News
space history and artifacts articles

Messages
space history discussion forums

Sightings
worldwide astronaut appearances

Resources
selected space history documents

Websites
related space history websites

  collectSPACE: Messages
  Exploration: Asteroids, Moon and Mars
  [Discuss] RS-25 (SSME) engines reallocated to SLS

Post New Topic  Post A Reply
profile | register | preferences | faq | search

next newest topic | next oldest topic
Author Topic:   [Discuss] RS-25 (SSME) engines reallocated to SLS
Robert Pearlman
Editor

Posts: 28779
From: Houston, TX
Registered: Nov 1999

posted 01-12-2012 08:15 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
Editor's note: In an effort to keep the topic [SLS] RS-25 (SSME) engine tests (Stennis A-1) focused on status updates, readers' feedback and opinions are directed to this thread.

Please use this topic to discuss the use of RS-25(D/E) engines for the Space Launch System.

Hart Sastrowardoyo
Member

Posts: 2365
From: Toms River, NJ,USA
Registered: Aug 2000

posted 01-12-2012 08:17 PM     Click Here to See the Profile for Hart Sastrowardoyo   Click Here to Email Hart Sastrowardoyo     Edit/Delete Message   Reply w/Quote
Will the core stage be reusable? Seems a waste to use components that are designed to be resuable - albeit with a more finite life than 55 missions they were originally expected to be used for - and throw them away after one use.

Robert Pearlman
Editor

Posts: 28779
From: Houston, TX
Registered: Nov 1999

posted 01-13-2012 04:39 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
The 15 space shuttle-used RS-25D engines will be lost with the first few test flights of the Space Launch System. The follow-on RS-25E engines will be streamlined to take into account their expendable use.

dabolton
Member

Posts: 269
From: Round Lake, IL, US
Registered: Jan 2009

posted 06-09-2013 06:58 PM     Click Here to See the Profile for dabolton   Click Here to Email dabolton     Edit/Delete Message   Reply w/Quote
Why are they having to fabricate a new adaptor if the engines came from the shuttle program; what happened to the equipment used to test during the shuttle program?

Robert Pearlman
Editor

Posts: 28779
From: Houston, TX
Registered: Nov 1999

posted 06-09-2013 07:37 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
As the space shuttle program was winding down, the A-1 test stand was modified to support testing of the J-2X engine, which will power the second stage of the Space Launch System (and was previously part of the Ares booster).

The changes were incompatible with the SSME (RS-25) engines.

The new adapter will allow testing of the RS-25 (D/E) while maintaining the J-2X hardware for future tests. This way, the A-1 stand will be able to be used for both engines, as needed.

JBoe
Member

Posts: 286
From: Edgewater, MD, USA
Registered: Oct 2012

posted 02-09-2014 07:47 AM     Click Here to See the Profile for JBoe   Click Here to Email JBoe     Edit/Delete Message   Reply w/Quote
When the 15/16 RS-25's become fitted and used on the SLS, will the J2X fill future SLS's or will there be a mixture of RS-25's and J2X's initially?

Robert Pearlman
Editor

Posts: 28779
From: Houston, TX
Registered: Nov 1999

posted 02-09-2014 09:47 AM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
The J-2X is not planned for use with the first stage of the SLS; after the stock of shuttle-legacy RS-25D engines are spent, they will be replaced with an upgraded version designed to be expendable (RS-25E).

As for the upper stage, Aviation Week reported in October 2013 that NASA no longer has an immediate need for the J-2X, which is considered overpowered for the first set of SLS planned missions.

Congress ordered an SLS able to lift 130 metric tons to low Earth orbit (LEO), which is a generally accepted requirement for launching a Mars mission. But for missions to the [vicinity of the] Moon, where a lot of Mars-precursor missions are being planned, a 105-ton SLS is probably sufficient, according to Steve Creech, May's deputy, who is responsible for finding other applications for the SLS.

One way to get to that capability would be with a "dual-use upper stage" carrying three or four RL-10s. All of them would ignite to get the payload — an Orion crew capsule, in-space habitat or lunar lander — into LEO, and then some subset of that number would fire for the trans-lunar injection to send the payload toward the Moon.

NASA hasn't ruled out using the J-2X for that portion of the trip, but it could be faster to develop the dual-use stage than the originally planned SLS upper stage powered by the J-2X, and a cryogenic propulsion stage (CPS) for getting into lunar orbit.

The RL-10 is currently used for the Centaur upper stage on the Atlas V and the second stage of the Delta IV.

Headshot
Member

Posts: 263
From: Streamwood, IL USA
Registered: Feb 2012

posted 02-09-2014 12:30 PM     Click Here to See the Profile for Headshot   Click Here to Email Headshot     Edit/Delete Message   Reply w/Quote
Will at least one of the SSMEs be preserved for posterity, or will they all be used and discarded?

Robert Pearlman
Editor

Posts: 28779
From: Houston, TX
Registered: Nov 1999

posted 02-09-2014 12:43 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
Congress instructed NASA to use all available and applicable shuttle assets in support of the Space Launch System, and so NASA intends to use all the flight-worthy RS-25D engines it has in inventory.

That said, there are shuttle-era SSMEs already on display in museums, including at the National Air and Space Museum (in the Moving Beyond Earth gallery), at the Kennedy Space Center Visitor Complex (in the Space Shuttle Atlantis exhibit) and at Space Center Houston (to name just three, there are others).

DavidH
Member

Posts: 1199
From: Huntsville, AL, USA
Registered: Jun 2003

posted 02-10-2014 10:15 AM     Click Here to See the Profile for DavidH   Click Here to Email DavidH     Edit/Delete Message   Reply w/Quote
As well as the U.S. Space & Rocket Center (ironically, Pathfinder has genuine engines while Atlantis, Discovery, Endeavour and Enterprise do not) and at Marshall Space Flight Center, visible on the USSRC bus tour.

Jim Behling
Member

Posts: 645
From: Cape Canaveral, FL
Registered: Mar 2010

posted 02-10-2014 10:43 AM     Click Here to See the Profile for Jim Behling   Click Here to Email Jim Behling     Edit/Delete Message   Reply w/Quote
Atlantis, Discovery, Endeavour have authentic and flown SSME nozzles. The powerheads, which are not visible while installed in an orbiter, were removed.

Robert Pearlman
Editor

Posts: 28779
From: Houston, TX
Registered: Nov 1999

posted 02-10-2014 10:48 AM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
Which, I understand, is the same for Pathfinder; only the two nozzles on Pathfinder flew on STS-1.

The displays I was referring to though are not the on the orbiters, but standalone, intact engines (though not necessarily assembled of parts that flew together on the same mission). For example, the National Air and Space Museum's SSME:

This SSME is made of up of components of SSMEs that have flown into space. The flights have included the first four Shuttle missions, the second Hubble Space Telescope repair mission, the missions that launched the Magellan and Galileo space probes, and the John Glenn flight. The engine was donated by Rocketdyne to the Smithsonian in 2004.
The California Science Center also has an SSME on display next to Endeavour.

All times are CT (US)

next newest topic | next oldest topic

Administrative Options: Close Topic | Archive/Move | Delete Topic
Post New Topic  Post A Reply
Hop to:

Contact Us | The Source for Space History & Artifacts

Copyright 1999-2014 collectSPACE.com All rights reserved.


Ultimate Bulletin Board 5.47a





advertisement