McDonnel-Douglas SM-11 Skögul Atmospheric-Escape Booster

SM-11 Skögul Atmospheric-Escape Booster 1

ROBOTECH Technical Files

by Peter Walker and Pieter Thomassen with Rob Morgenstern

edited by Tim Wing


  • Valkyrie Booster reference file
  • Valkyrie Booster gallery

Designation: McDonnel-Douglas SM-11 Skögul Atmospheric-Escape Booster

I. Dimensions.

  • Total Length: 13.6 meters
  • Total Width: 4.2 meters
  • Total Height: 9.1 meters
  • Weight: 24.5 metric tons (dry, stand-alone), 161.2 metric tons (fueled, with Valkyrie attached).

II. Type:

  • Unmanned Booster unit for VF-1 Valkyrie mecha. Can be fitted on all Valkyries (save the AEW versions) provided these are not mounted with Super, Strike or Armor equipment.

III. Service History

  • Served with the UN Spacy from 2009 until 2017, and with the UEDF Tactical Armored Space Corps from 2018 until 2024.

SM-11 Skögul Atmospheric-Escape Booster 5IV. Propulsion:

  • 4 x Rolls Royce/Rocketdyne BV-3 engine clusters, each cluster containing 4 P&W/Nakajima FF-900 fusion ramjet/scramjet/reaction engines with 220.73 kN thrust each for a total of 3531 kN.
  • 2 x Nakajima NBS-1 high-thrust vernier thrusters, one on either side.
  • Powersource: fed from the Valkyrie’s protoculture energizers.

V. Performance:

  • Maximum acceleration: 2.5 g at take-off, 4 g cruising (typical).
  • Delta-v capacity: 11.8 kps.

VI. Electronics:

  • None of note, and is dependent on Valkyrie systems.

VII. Armor:

The skin of the Valkyrie booster is composed of an advanced titanium-steel alloy. The skin stops all small arms fire, provides fair protection against heavier infantry weapons, such as a 12.7mm machinegun round, and poor resistance to light mecha-mounted weaponry, such as the Zentraedi 22.3mm HE autocannon round.

VIII. Development:

While the VF-1 Valkyrie was, by itself, capable of reaching low Earth orbit, it could do so only by exhausting nearly all its own reaction mass. As there was a need for the Valkyries to be able to transport themselves into a higher orbit (the ARMD platforms rarely descended to such low an orbit that an unaided Valkyrie could rendez-vous with them) an orbital booster was developed that gave the Valkyrie the capability to ascend as high as a geostationary orbit.

The booster took the form of a large attachment to the rear of the Valkyrie, with four large engine housings, each of which contained four small fusion engines. The engines drew their power from the Valkyrie’s own protoculture power systems. These engines would serve as reaction engines during take-off, then revert to ramjet mode until a speed of Mach 3 was reached, convert to a scramjet configuration, and then slowly reconvert to a reaction engine as the vehicle left the atmosphere. This mode of operation meant that the atmosphere provided a large part of the reaction mass required by the vehicle. For the atmospheric stages, the upper engines used inlets on top of the boosters, while the lower engines were fed through the Valkyries own fusion turbines in stationary mode. Attitude control was by the Valkyrie’s thrusters and by vectored exhaust, and by two vernier thrusters built into the booster’s lower sides. As the Valkyrie needed to convert into a partial Guardian configuration in order to mount the booster, and because the weight was concentrated to the rear, the vehicle could not use a runway. Instead, a tracked launch platform was developed which launched the craft from a rail. After detachment from the Valkyrie, the booster could be recovered by shuttle and reused.

M101 Sagittarius Launch PlatformThe booster was never meant for combat launches, only for ferry flights. As such it saw much service in the UN Spacy during the reconstruction years, when a dearth of cargo shuttles made the booster the most economic manner of ferrying a Valkyrie to the orbiting Zentraedi and Terran vessels.



Robotech (R) is the property of Harmony Gold. The Super Dimension Fortress Macross (R) is the properties of Big West Advertising and Studio Nue. This document is in no way intended to infringe upon their rights.

Original artwork by: Shoji Kawamori, Miyatake Kazutaka, Haruhiko Mikimoto and Hidetaka Tenjin

Acknowledgement is extended to the work of Egan Loo and the Macross Compendium. Egan Loo is given all credit for all quotes and paraphrasing of the Macross Compendium that has been utilized in this publication. 

Images Courtesy of Chad Wilson (Marchly) and the Macross Mecha Manual. Chad Wilson is given all credit for all images from the Macross Mecha Manual that have been utilized in this publication.

Acknowledgement is extended to Peter Walker, Pieter Thomassen and Robert Morgenstern of the unofficial Robotech Reference Guide. Peter Walker, Pieter Thomassen and Robert Morgenstern are given credit for all quotes and paraphrasing of the unofficial Robotech Reference Guide that has been utilized in this publication. 

Images From – Macross Perfect Memory 

Content by Peter Walker and Pieter Thomassen with Rob Morgenstern, edited by Tim Wing

Copyright © 2005, 2004, 1999, 1997, 1995 Peter Walker and Pieter Thomassen with Rob Morgenstern; 2015 Tim Wing