Orlan-M

The Russian spacesuits in use aboard the International Space Station is the latest variant of the Orlan series, the Orlan-M (and soon its successor, the Orlan-MK).

Orlan is Russian for “Sea Eagle”. All Russian space- and pressure suits are named after birds. The suit worn on the Soyuz spaceship is the Sokol or “Falcon”. Other previous suits have been:

  • «Стриж», Strizh or “Swift,” intended for the Buran space shuttle.
  • «Ястреб», Yastreb “Hawk” and «Беркут», Berkut “Golden Eagle” suits worn on Voshkod and early Soyuz flights.
  • «Кречет», Krechet or “Gerfalcon” suit intended for the Soviet Moon landing program.

Like previous Orlan versions, the Orlan-M and -MK made by the Research, Development & Production Enterprise Zvezda (НПП «Звезда»), the company which has produced all Russian spacesuits and survival equipment since it was established on 2 October 1952. They are located in Tomilino, Moscow region.

Terminology

The Russian word for spacesuit is skafandr, скафандр (plural skafandry, скафандры). The “M” stands for modernized, modernizirovannyi, модернизированный.

Russians don’t seem to have a formal acronym for a spacewalk (as in EVA). These terms are generally used:

  • VKD, vnekabinnaya ili vnikorabel’naya deyatel’nost’, внекабинная или вникорабельная деятельность – translating roughly as out-of-cabin or -ship activity/work. (Thanks to Olaf Neumann for this)
  • Vykhod v otkrytyi kosmos, выход в открытый космос – “going out into open space” (from Levan)
  • Someone on the Novosti Kosmonavtiki forum suggested: ВКД (Внекорабельная Деятельность).
  • I have also seen just “vykhod” used in the NASA On-Orbit Reports (выход, plural выходы – literally “exits”). Perhaps this is more of a slang or shortened term.

I will usually use VKD to complement the NASA EVA acronym. I use “spacewalk” as a generic term, and “EVA” for specifically American spacewalks (i.e. wearing NASA EMUs).

Development

ESA and Zvezda had begun development work on a joint spacesuit called EVA SUIT 2000 in the early 1990s, but this was cancelled late in 1994 due to financial constraints on both sides. In 1995, when the Shuttle-Mir and ISS programs were underway, Zvezda decided to modify its next batch of Orlan-DMA suits destined for Mir with various improvements. Orlan-M suits numbered 4, 5 and 6 were delivered to Mir in 1997 and used for 36 spacewalks.

Zvezda and the U.S. manufacturer of NASA’s EMU suits, Hamilton-Sundstrand have also co-operated in ISS spacesuit development. Two Orlan suits were delivered to support training in the NASA hydrolab. The Orlan was also enabled so it could be used in the U.S. joint airlock, Quest, via a portable unit called the BSS-2M, БСС-2М; it is a suit control panel (БУС, BUS) and a bundle of hoses with electric cables. Parts from the U.S. EMU spacesuits can also be used in the Orlan-M, e.g. the headlamps and drinking water supply.

A main characteristic of all Russian Orlans is the duplication of all main life-support systems. There are two fans, two pumps, two hermetically-sealed shells, two sealed glass visors, two oxygen cylinders. Even if the metallic cuirass, made from an aluminum alloy, suddenly on cracks for some reason, this is not a disaster. From inside it is covered with a rubberized fabric.

Orlan-M technical data

The Orlan-M is a spacesuit of the semi-rigid type, with a hard aluminium-alloy torso (cuirass) and arms and legs made of a softer material. It is an improved version of the previous spacesuit, the Orlan-DMA, taking into account the operational experiences of those using this spacesuit. It is strictly for zero-gravity use; its current design could not be used on the Moon or Mars as it is too heavy.

  • The Orlan-M can accommodate a greater range of anthropometric sizes: 165 cm to 190 cm height (instead of 185 cm for the DMA) and up to 112 cm for chest diameter (instead of 108 cm). The Orlan can be adjusted to fit different wearers by lengthening or tightening straps in the arms, legs and torso (as shown in the diagram below). Maximum chest diameter is 112 cm; maximum height is 190 cm. The arms can also be removed and replaced with new ones if damaged (e.g. by a meteorite or space debris puncture).
  • Radio communications have been modified so that two cosmonauts can speak and listen to each other simultaneously (which they couldn’t in the previous Orlan version).
  • The metallic cuirass (the suit’s hard aluminium-alloy torso) is increased in size as are the arm and leg openings for the greater range of wearers’ heights. On the cuirass are fixtures for attachment of the USK, Cosmonaut Self-Rescue Device (УСК).
  • An additional visor enhances the upper field of view and helps prevent the original one from misting up.
  • A variable-length safety tether widens the cosmonaut’s area of operation.
  • Improvements were also made in the ankle and pressure bearings; mobility and strength of the pressure gloves; a more reliable wrist pressure disconnect; back-up pump; snap hook for the safety tethers; fan, radio set, and the absorption capacity of the CO2 cartridge.
  • The Orlan can be used in both the Pirs and U.S. Quest airlocks (the U.S. EMU can only be used in Quest).
  • Some American EMU equipment, such as a 350 ml drink bag, side headlights and “Pampers” urine-absorbing garment, can also be worn.
  • If a spacesuit’s serial number has a last even digit (2, 4, 6, etc.), then the spacesuit has blue stripes, if a last odd digit (1, 3, 5, etc.), then red stripes – a tradition of NPP Zvezda. (Via Anik)
  • From a webpage at the Made in Russia site:

    Scientists pay special attention to ensuring the durability of spacesuits. A tiny particle of one tenth of one millimeter flying in outer space at 20 kilometers a second or so can break the spacesuit. Tests carried out on the Earth have proved this. In special devices tiny particles were accelerated at several kilometers an hour and were directed on a fragment of the fabric used for making the spacesuits. Particles of half millimeter in diameter broke through all the layers of the fabric easily. Though arrows of that size are unlikely to hit the cosmonaut’s spacesuit the designers have taken into account such a possibility. If the spacesuit is damaged, a special system is switched on and will maintain the required pressure inside the spacesuit during 30 to 50 minutes, depending on the size of the hole. This will make it possible for the cosmonaut to return to the station.

  • From ESA’s EVA Blog:

    According to Gerhard Thiele, sneezing inside the EVA helmet is to be avoided at all costs “It’s a mess!” And if you get an itch, you might be able to rub up against the spacesuit, but other than that, there is not a lot you can do in an American EVA spacesuit. If however you are lucky enough to be in a Russian Orlan suit, there might be a solution. “There is a bit more room in the Orlan,” Thiele explained. “You can lean to one side and pull your arm out of the glove and sleeve. But mostly you are so concentrated during the spacewalk, that you might not even notice an itch.”

  • Helmet lights were first introduced on Orlan-DM spacesuits (first use: 2 August 1985) on the Salyut-7 station. These lights had two filament lamps in each light. They were used in subsequent spacesuit versions until 22 February 2007 (Orlan-M). From then, a different type of light with 42 diode lamps in each light was used. A combination of Russian and US lights was also used on some ISS spacewalks. (Source)
  • The outer layer is made of Phenylon®, as described in this Nasaspaceflight.com post:

    As I understand it Phenylon® is a Russian tradename for a material equivalent to Dupont’s Nomex® 0150 otherwise know to chemists as poly(m-phenylene isophthalamide) or PMPI for short.

    This is a high-performance polymer, with high thermal and mechanical resistance, described by Dupont as “inherently flame-resistant, high-temperature fiber that will not melt, drip or support combustion in air. It also delivers outstanding resistance to a broad range of chemicals and is offered in paper, felt, fabric and fiber forms”

    The natural color of Nomex® is usually described as “off-white” or “ivory,” and many variants are classed as non-dyeable.

The Orlan operates at a pressure of 0.4 atmospheres (EMU at 0.3 atm.), enabling a pre-breathe time of only 30 minutes (in the EMU pre-breathe is 12 hours in the Joint Airlock, or 4 hours in the EMU itself). The drawback is that the higher pressure means that the Orlan is somewhat more difficult to move in.

Before climbing into the Orlan, the wearer first dons long white underwear, then the blue-colored cooling garment, which is interlaced with cooling tubes through which water flows.

The Orlan is easily donned; the user floats into it via the backpack, whose door swings open like a refrigerator’s. All essential equipment in the backpack – hermetically-sealed shell, fans, water pumps, pressure regulators, oxygen cylinder, radio, etc. – has backups/duplicates. (NASA considers its EMU’s systems completely reliable, so they are not duplicated.)

The suits must be maintained and repaired in orbit by the on-board crew with special tools; they are not returned to Earth for maintenance as there is no room in the Soyuz spaceship. The Orlan has a useful life of 4 years or up to 15 EVAs, limited by its pressure bladder which is made of natural rubber (which deteriorates over time).

The suits are usually bundled into a Progress cargo ship and burn up when the ship is undocked and enters the atmosphere. Unfortunately this means that few suits worn in orbit will make it to museums, though removable parts of the suits (gloves, visors) can be souvenired and taken back to Earth.

A new scheme is to fit the suit to be discarded with amateur radio communications equipment, push it from the ISS during a spacewalk and turn it into a “SuitSat,” an orbiting Amateur Radio transmitter! The first was “launched” on 3 February 2006 by Expedition 12, to orbit for a few weeks before atmospheric drag pulled it towards Earth.

During Expedition 14’s stay in 2006, Suit №26 developed a leak and spare parts arrived on Progress M-58: two new arms that were attached by Mikhail Tyurin on 14 November (see photo ISS014-E-07859.jpg). A new leg was brought up on M-59. This would prolong the suit’s life until December 2007 (originally set to expire in December 2006).

Mir/ISS suit Orlan-M
Official name Orlan-M spacesuit, «Орлан-М» скафандр
Description This spacesuit of the semi-rigid type was an Orlan-DMA spacesuit modification. The Orlan-M design took into account the experience of Orlan-DMA operations on Mir and the additional requirements imposed by operations on the ISS. The suit underwent the following modifications:
  • The suit’s dimensions were enlarged in the waist area and the entry hatch was moved upward.
  • An additional helmet-top window and protective glass for the main window were introduced.
  • A calf bearing and the third pressure bearing (elbow) on the suit arm were introduced.
  • One of the safety tethers was given variable length.
  • CCC capacity was increased.

Power supply, radio communication and telemetry were available for self-contained mode (from the backpack) and via the 25-m electrical umbilical from the station. Owing to the above, the service characteristics (mobility, donning/doffing, field of view, etc.) were improved. The anthropometric ranges of chest circumference and height were improved (96-112 cm and 164-190 cm, respectively). The suit was provided with attachment points for SAFER.

Utilisation (operations)
  • Mir: 1997-2000 for 18 paired EVAs
  • ISS: 2001-31 December 2002 for 9 paired EVAs
Development and operation dates Development and tests: 1995-1997. Nominal operations: 1997-up to the present
Quantity of manufactured spacesuits (as at 31 December 2002)
  • Test and training models: 17
  • Flight models: 7
Main technical characteristics of the Orlan-M spacesuit
Nominal duration of the autonomous mode 7 hours
CO2 absorption cartridge operating time (with airlock time included) 9 hours
Suit positive pressure
  • Nominal mode: 392 hPa
  • Emergency mode: 270 hPa
Spacesuit pressure
  • Primary mode: 400 hPa
  • Reserve mode: 392 hPa
Oxygen available (main and back-up) 1 kg each
Amount of O2 emergency supply, manually activated (kg hr1−1) 2
Cooling water available 3.6 kg
Assured heat removal
  • Average: 350 W
  • Maximum: Up to 600 W
Total consumed power by the suit systems Up to 54 W
Quantity of telemetry measured parameters 29
On-board system
  • Mir: BSS-2M
  • ISS: BSS-4
Spacesuit weight (wet) ~109 kg
Service life Up to 15 VKDs (EVAs) over 4 years (no return to the Earth)

(Source: Russian spacesuits.)

Diagrams

Illustrations scanned from Russian Spacesuits:

Miscellaneous images:

Photo gallery

  • Orlan-M (via ESA)Orlan spacesuit.
  • Vladimir Dezhurov and Frank Culbertson in Orlan cooling garmentsFrank Culbertson, and Vladimir N. Dezhurov (ISS-3) wearing thermal undergarments for the Orlan. The blue cooling suit (KVO, КВО, костюм водяного охлаждения) is worn over the thermal underwear.