Released in 1980, LEGO 6901 Mobile Lab is a distinctive six-wheeled scientific exploration vehicle from the early Classic Space era. BrickLink catalogs the set with 117 parts and 2 minifigures, while alternative inventories use different counting methodologies. The crew consists of one red and one white Classic Space astronaut.
With its predominantly light-gray construction, transparent-green windows, laboratory-style rear compartment and large radar dish, 6901 has a very different character from the spacecraft that dominated the Classic Space lineup.
Detailed Review
Design and build
The set builds a substantial six-wheeled mobile laboratory finished primarily in light gray. Rather than functioning as just another lunar rover, the design resembles a self-contained scientific and communications vehicle capable of carrying its Classic Space crew and equipment.
The front driving section is complemented by a large enclosed laboratory area featuring transparent-green elements and hinged sections. The vehicle carries a large 4x4 light-gray radar dish, rooftop antenna and an articulated mechanical arm assembly, reinforcing its scientific exploration role.
The inventory confirms the dish, multiple hinged bricks and a multi-piece articulated arm mechanism. Printed detailing is particularly attractive. 6901 contains two light-gray 1x2 Classic Space logo bricks (3004p90) and two light-gray 3x2 Classic Space logo slopes (3298p90). This gives the vehicle four prominent Classic Space emblems rather than relying on stickers.
The set also includes several period accessories, including a black radio, a spanner/screwdriver and three light-gray Space Gun/Torch pieces.
The result is unmistakably early Classic Space: relatively simple construction techniques, but considerable character and functionality created from a modest selection of bricks, plates, hinges and specialised elements.
Playability and display
Excellent for a vehicle of this size.The six-wheel configuration, opening laboratory structure, articulated equipment, radar dish and two-person astronaut crew offer plenty of possibilities for exploration and scientific-mission play. The included red and white astronauts also provide considerably more presence than a single-minifigure vehicle. For display, 6901 works particularly well alongside the larger Classic Space bases and spacecraft. Its predominantly light-gray appearance and substantial ground-vehicle proportions contrast beautifully with the blue-and-gray spacecraft of the period.
Strengths
- Distinctive early Classic Space scientific exploration vehicle.
- Excellent functionality relative to its size.
- Includes two astronauts, one red and one white.
- Four prominent printed Classic Space logo elements.
- Large radar dish and articulated mechanical equipment add considerable character.
- Attractive transparent-green elements give the Mobile Lab a distinctive appearance.
- Excellent companion vehicle for an early Classic Space display.
Weaknesses
- Construction is simple compared with modern LEGO vehicles.
- The predominantly light-gray colour scheme is less visually dramatic than some Classic Space spacecraft.
- Several smaller accessories and mechanical-arm components are easily separated from the set.
- Printed Classic Space logos can show wear after decades of play.
- Correct vintage astronaut helmets can be difficult to find in excellent condition.
Community reception
6901 occupies an interesting position within early Classic Space. Rather than being another spacecraft, the set expands the theme's exploration concept with a dedicated mobile laboratory.That distinctive role, combined with two astronauts, multiple printed Classic Space elements and a functional equipment-heavy design, makes it particularly appealing when displayed as part of a broader vintage Classic Space collection.
Overall rating: 8.5 / 10
An excellent early Classic Space ground vehicle with considerable charm and playability.6901 may not have the immediate flagship presence of 928 Galaxy Explorer, but its unusual laboratory concept, six-wheel design, two-astronaut crew and generous assortment of printed Classic Space elements make it much more interesting than a typical small rover.For collectors assembling the early Classic Space range, Mobile Lab is a highly desirable supporting set and an excellent display companion to the larger spacecraft and bases.
Collector’s Inspection Guide – What to Check
When buying used/complete or sealed examples, carefully inspect these points (condition dramatically affects value):
- Printed Classic Space logo slopes (3298p90, Light Gray) – The set contains two light-gray 3x2 slopes carrying the Classic Space logo. Check carefully for fading, scratching and wear to the gold planet/rocket printing.
- Printed Classic Space logo bricks (3004p90, Light Gray) – Two 1x2 printed logo bricks are also included. As with other early Classic Space sets, strong gold printing is much more desirable than heavily faded examples.
- Red Classic Space astronaut – Check the torso logo, red air tanks and early-style helmet carefully. The parts inventory identifies the red astronaut with the early thin-chinstrap helmet style.
- White Classic Space astronaut – Check carefully for yellowing or discoloration of the white plastic, along with torso-print wear, cracks in the helmet and damage to the air tanks. The original inventory identifies the same period thin-chinstrap helmet style for the white astronaut.
- Light Gray 4x4 Radar Dish (3960) – A prominent component of the Mobile Lab. Check the dish for cracks, heavy scratches or damage around the central mounting point.
- Mechanical arm assembly – The vehicle uses a collection of vintage light-gray arm components, including five straight arm pieces, an arm with tow-ball socket and the associated mounting components. Check that all are present and that the fingers and joints are intact.
- Transparent-green elements – These contribute strongly to the characteristic appearance of 6901. Inspect them for heavy scratching, cracks and cloudiness.
- Six wheel assemblies – The inventory specifies six light-gray wheel assemblies with red wheels and black tyres. Check that all six are complete and that tyres are not cracked, badly deformed or substituted.
- Small astronaut accessories – Check for the black radio, black spanner/screwdriver and three light-gray Space Gun/Torch pieces. These small accessories are particularly easy to lose.
- Light Gray Antenna 4H – Round Top (3957a) – Verify that the correct early round-top antenna is fitted rather than a later variant or replacement.
- Hinges and moving sections – The vehicle uses four swivel hinge bases and four matching tops. Check that the hinged sections still move and hold their position correctly and that none of the components are cracked.
- Completeness and authenticity – Original instructions significantly improve collector appeal. BrickLink confirms that 6901 was issued with instructions. Check visible components carefully for inappropriate modern replacements.
- Overall light-gray condition – With so much exposed vintage light gray, mismatched shades, discoloration, scratches or replacement pieces can be very noticeable on the completed model.
- Overall cleanliness and odor – As with other vintage Classic Space sets, inspect for accumulated dirt, smoke odor, moisture damage and poor long-term storage.
A high-quality 6901 should ideally have strong gold printing on all four Classic Space logo elements, clean red and white astronauts, intact mechanical-arm components and consistent vintage light-gray pieces.
Rare / Notable Elements and Approximate Current Market Values (late 2026)
Values fluctuate considerably according to condition. The elements below are the parts I would pay particular attention to when assessing a collector-quality 6901. Exact current sale values should always be checked against BrickLink/BrickOwl and recent sold listings.
| Element | Notes | Collector Importance |
|---|---|---|
| 3298p90 Light Gray 3x2 Classic Space Logo Slope (x2) | Two are present in 6901. Their large printed logos are visually prominent, making print quality particularly important. | High |
| 3004p90 Light Gray Classic Space Logo Brick (x2) | Classic early Space printed element. Bright and complete gold printing is preferred. | High |
| White Classic Space Astronaut with air tanks | One of the two original crew members. White-plastic condition, torso printing and early helmet are important. | High |
| Red Classic Space Astronaut with air tanks | Second original crew member. Check helmet, tanks and torso-logo condition. | High |
| Light Gray mechanical arm components | A collection of period mechanical-arm pieces forms an important part of the Mobile Lab's equipment. Broken or missing fingers reduce completeness. | Medium–High |
| 3960 Light Gray 4x4 Radar Dish | Large and visually prominent equipment piece mounted on the laboratory. | Medium |
| 3957a Light Gray Round-Top Antenna | Period-correct early antenna variant specifically listed in the set inventory. | Medium |
| Original Instructions | BrickLink separately catalogs the original 6901 instructions; condition is important for a premium complete example. | High for collectors |
| Original Box | Particularly desirable when building a complete vintage example. BrickLink records original-box information for 6901. | Very High for complete examples |
The real highlights of 6901 are the four printed Classic Space logo elements and the complete red-and-white astronaut crew.
The mechanical-arm components and large radar dish are also important because missing pieces immediately affect the characteristic appearance and functionality of the Mobile Lab.Unlike 928, 6901 does not contain the rare 3144 Light Gray Antenna with Side Spokes that we discussed earlier. BrickLink's inventory specifies the standard 3957a Light Gray Antenna 4H – Round Top.
That distinction is worth making on LEGObrickz so collectors do not confuse the two antennas. Bottom line for collectors: 6901 Mobile Lab is a charming and distinctive example of early Classic Space ground exploration. Prioritize strong Classic Space logo printing, complete period-correct astronauts, intact mechanical-arm components and consistent vintage light-gray pieces.
A clean, genuinely complete example with original instructions and box makes an excellent addition to a serious Classic Space collection.
Overall rating: 8.5 / 10
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