CNC Machining for the Space Industry

The space supply chain has a capacity problem. Launch cadence keeps climbing, satellite constellations keep growing, and the primes and tier-1s building that hardware are actively hunting for vetted, certified small machine shops that aren’t already locked into prime work. If you’re a propulsion, structures, or avionics engineer — or the supply chain manager trying to qualify your next supplier — this guide covers what actually matters when you put machined flight hardware out for quote.

Why space machining is different

Every machined part carries requirements, but space hardware stacks them: it must survive launch vibration and acoustic loads, function across extreme thermal cycles, hold dimensional stability in vacuum, and do all of it at minimum mass — because every gram costs real money to orbit. That translates to four things a supplier must demonstrate, not just claim.

• Tight-tolerance discipline: not the ability to hit a tight tolerance once, but the inspection system to prove every part in the lot holds it. In-process checks during the run, final inspection on calibrated CMMs, and documentation a quality engineer can audit.
• Material integrity and traceability: certified material with mill certs that trace every part back to its heat lot. Space programs don’t accept “equivalent” material substitutions discovered after the fact.
• Process control: documented, repeatable processes — the core of AS9100D — so part 500 matches part 1.
• Data security: drawings and models for space systems are frequently export-controlled. The shop holding them must be ITAR registered, and increasingly, CMMC-certified.

Materials: what flies, and what it takes to machine it

Aluminum 6061-T6 and 7075. The workhorses of spaceflight structures. 6061-T6 offers excellent machinability, weldability, and thermal performance for housings, brackets, and chassis. 7075 brings nearly twice the strength for structural parts that earn their mass — at the cost of lower corrosion resistance, usually addressed with chromate conversion or anodize. Both machine fast in capable hands, which is why aluminum flight structures reward shops with high-speed spindles and aggressive-but-controlled toolpaths: an 18,000 RPM spindle and modern CAM make thin-wall aluminum work economical.

Titanium (Ti-6Al-4V). Where temperature, strength, and mass intersect — propulsion brackets, high-load fittings, fastener-critical interfaces. Titanium punishes impatient machining: it work-hardens, holds heat at the cutting edge, and demands rigid setups, sharp tooling, and disciplined feeds and speeds. Ask any prospective supplier specifically about their titanium experience; it is not aluminum with a higher price.

Inconel and nickel superalloys. The propulsion-side materials — combustion devices, hot-gas paths, high-temperature fasteners and fittings. Inconel 718 retains strength at temperatures that anneal steel, which is exactly why it’s miserable to machine: tool life is measured in passes, not parts. Shops that quote it casually either know precisely what they’re doing or haven’t machined it. At Mountain CNC, nickel alloys are quoted case-by-case — deliberately — so every Inconel job gets engineering review before a price goes out the door.

Engineering plastics: PEEK and Ultem. Insulators, isolators, wear surfaces, and low-outgassing non-structural components. PEEK machines beautifully but moves with heat and moisture; tolerance expectations and fixturing must account for it.

The full material range — including copper alloys for thermal hardware and stainless families for fluid systems — is on our materials page.

Tolerances and the metrology that backs them

A tolerance on a drawing is a promise; metrology is what keeps it. Optical benches, propulsion interfaces, and precision mechanisms routinely carry true-position and flatness callouts that demand more than calipers and a surface plate. Before qualifying a supplier, ask what the parts will be inspected on.

Our answer: a Hexagon 9.15.8 Scan+ 5-axis CMM (36" × 60" × 32" envelope) with high-performance tactile scanning for full-form verification, a Keyence LM-X multisensor measurement system for high-throughput optical inspection, and a Keyence XM-5000 CMM at the machine for in-process checks — backed by profilometry, optical comparison, and calibrated gaging. First article inspection per AS9102 comes standard with aerospace work; full dimensional reports are available where the program requires them.

Five-axis machining and why your flight hardware wants it

Mass-optimized space parts trend toward geometry that three-axis machines handle badly: compound angles, thin webs, undercuts, and organic pocketing straight out of topology optimization. Simultaneous 5-axis machining attacks those features in one or two setups instead of five or six. Fewer setups means fewer opportunities for fixturing error, better feature-to-feature relationships, and shorter schedules.

Our 5-axis cell runs on Doosan DVF 6500 and DVF 5000 simultaneous 5-axis machining centers — 18K high-torque spindles, 120- and 60-tool changers — with a CubeBox DR automation system feeding the DVF 5000 for unattended pallet runs. That automation matters for space work in a specific way: it lets a small shop deliver production quantities on schedule without surrendering the per-part inspection discipline that flight hardware demands. The complete fleet — roughly 30 CNC machines including horizontal milling and dual-spindle live-tool turning — is on the equipment page.

ITAR for space programs, in plain terms

Most spacecraft, launch vehicle, and satellite technical data falls under U.S. export control — either ITAR (U.S. Munitions List, which covers most spacecraft systems) or EAR. For a machine shop, the practical consequence is simple: if a supplier isn’t ITAR registered, you cannot legally send them your controlled drawings.

Registration means the shop is on file with the State Department’s Directorate of Defense Trade Controls, renews annually, restricts controlled technical data to U.S. persons, and maintains documented internal controls covering how drawings are received, stored, and destroyed. Mountain CNC holds DDTC registration M48464, current through 2026. Ask for the registration letter from any supplier who claims ITAR status — and be wary of anyone advertising “ITAR certified.” There is no such certification; registration is the only thing that exists, and suppliers who don’t know that distinction haven’t spent much time with the regulation.

AS9100D: the qualification shortcut

Supplier qualification is expensive for both sides. AS9100D exists to compress it: a current certificate from an accredited registrar tells your quality organization that configuration management, nonconformance control, FOD prevention, counterfeit-part controls, and first article discipline have already been independently audited. Mountain CNC is AS9100D certified (which fully encompasses ISO 9001), CAGE code 1VYF7, machining continuously since 1997.

When you’re building a supplier packet, the gates are usually: capability review → quality system verification → first articles per AS9102 → probationary orders → production release. We keep the capability statement, certificates, and registration letters ready for download because the fastest qualification is the one where the supplier hands you everything on day one.

CMMC Level 2: the next gate, and most shops aren’t ready

Space work adjacent to defense programs increasingly involves Controlled Unclassified Information, and the DoD’s CMMC program is converting NIST SP 800-171 from a self-attested checkbox into a third-party-audited certification. As primes flow CMMC Level 2 down through their supply chains, machining suppliers without it will quietly disappear from bid lists.

Mountain CNC is completing CMMC Level 2 certification in 2026, with NIST SP 800-171 controls already implemented and third-party assessment scheduled. If your program needs CUI-capable machining capacity in 2026 and beyond, qualifying us now means your supply chain doesn’t wait at that gate.

From prototype to flight production

Space programs iterate. The shop that machined your prototype in genuine flight material — not a 3D-printed approximation — has already de-risked your production: the toolpaths, fixturing, and inspection plan exist, and the part’s machining behavior is known. Our prototyping work runs on the same machines, same metrology, and same quality system as production, so the transition is a quantity change, not a process change. Anodize, chromate, passivation, plating, and heat treat are managed through our vetted finishing network under one purchase order.

The supplier-vetting checklist

Whether you qualify Mountain CNC or someone else, these are the questions that separate shops that can machine space hardware from shops that say they can. Steal this list for your next supplier review.

• Show me your AS9100D certificate. Current, from an accredited registrar, scope covering CNC machining. An expired or “in transition” certificate is a no.
• Show me your ITAR registration letter. Not a verbal claim. The DDTC letter has a registration code and an expiration date. (Ours is M48464, downloadable from our ITAR page.)
• What CMM will my parts be inspected on, and when was it calibrated? If the answer is calipers and a height gage for true-position callouts, keep looking.
• Who supplies your material, and can you provide mill certs traceable to heat lot? Material traceability failures are how counterfeit metal ends up in flight hardware.
• What's your titanium and nickel-alloy experience, specifically? Ask for the materials they ran last quarter. Exotic-alloy competence can't be improvised on your part.
• How do you handle controlled technical data? Who can access drawings, where do they live, how are they destroyed at job end. ITAR registration without real internal controls is paperwork.
• What happens when a part goes nonconforming? You want to hear: documented NCR process, customer notification, root-cause corrective action — not “we remake it and don't charge you.”
• Can you scale this part to production? Pallet automation, lights-out capability, and capacity headroom are what turn a prototype vendor into a program supplier.

A supplier comfortable with every question on this list in a single phone call has answered the real question: they've been audited before, by people harder to satisfy than you.

Why Colorado's Front Range matters to your supply chain

Colorado hosts one of the densest aerospace and space-industry clusters in the country — second only to California in aerospace employment concentration, with launch providers, satellite manufacturers, propulsion startups, and major primes operating along the Front Range corridor from Colorado Springs through Denver and Boulder to Fort Collins. That density is a supply chain advantage that out-of-state machining vendors can't replicate.

Proximity compresses everything: same-day part delivery instead of freight schedules, an engineer driving forty-five minutes to watch a first article come off the machine instead of flying in, and face-to-face DFM reviews when a design is still cheap to change. For iterative programs — which is to say, all space programs — a certified machining partner an hour away beats an equivalent one three time zones away every single week of the schedule.

Mountain CNC machines from Loveland, Colorado — in the middle of that corridor, machining continuously since 1997, with the certifications, metrology, and capacity described in this guide. The shop is open for qualification visits; come walk the floor, or take the video tour first.

Frequently asked questions