Ostranauts transponder guide: IFF registration, stolen-ship flags, Ship Broker replacement steps, Polaris VDX-01 value, and when to broadcast or go dark.
Your A.J. walks through flipping salvaged hulls — the same registration path stolen-ship players need before buying a broker transponder.
~13 min read
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The Ostranauts transponder — formally an IFF (Identification Friend or Foe) unit — is the legal ID card your hull broadcasts to stations and patrol craft. Salvage a derelict without fixing registration and you inherit a stolen-ship flag: the hull flies, but ATC scrutiny, PASS travel limits, and barter zones treat you like a pirate until you understand what transponders can and cannot fix. This page walks the highest-intent search path — buy, wire, toggle, and live with a flagged hull — verified August 16, 2026 · Steam · Official wiki.
| Fact | Detail |
|---|---|
| Primary keyword | ostranauts transponder · stolen ship registration |
| Legal ownership | Purchased via Ship Broker Kiosk — Azikiwe Commercial, OKLG |
| Replacement part | XPDR Transponder + Antenna (both required for lawful flight) |
| High-value loot | Polaris "VDX-01" IFF unit — ~$29,000 kiosk value |
| Salvage permit | OKLG License Kiosk — required to sell high-value stripped gear legally |
| Toggle effect | Transponder ON = identifiable; OFF = harder to trace, more patrol interest |
| Cannot fix | Full ownership on a stolen hull — no broker sale, no PASS home base |
Every ship in Ostranauts has a registration identity stored in OGSIO databases — the in-universe ship registry Ogiso maintains. The IFF transponder (shown in-game as an XPDR unit on many hulls) is the radio that broadcasts that identity to local traffic control, security services, and other vessels.
| Component | Role |
|---|---|
| XPDR Transponder | Stores and broadcasts registration ID tied to a legally owned hull |
| Antenna | Required to transmit — transponder alone does not reach ATC |
| Nav Console | Displays registration alerts, hail lists, and ownership warnings |
| Ship Broker — Transponder tab | Sells duplicate/replacement units for ships you own |
IFF is not a combat IFF overlay from a military sim — it is paperwork with a radio. Stations use it to decide whether you are cleared to dock, whether PASS ferries should list you, and whether patrol craft should invest fuel in a closer look. A missing transponder is suspicious; a transponder tied to another hull's registration is suspicious in a different way.
Assuming you actually own the hull (see the next section for why salvage complicates this), the FAQ on the official wiki lists the minimum legal kit: at least one ship battery, conduit to every powered device, a registered transponder, an antenna, a nav console, an RCS intake, a gas canister, and an RCS thruster. Atmospherics are optional on a bare vacuum tug but mandatory once you pressurize a compartment.
Power and registration are separate problems — a wired transponder on a stolen hull still broadcasts something, just not a clean bill of health.
Most players hit this after the character-creation poker prize: you start in a hull that was never sold to you through Ogiso. Strip a derelict in the boneyard and attach it to your tug, and you get the same problem — the frame never entered your name in the registry.
Ship Ownership on the official wiki draws a hard line: legal ownership comes from the Ship Broker Kiosk in Azikiwe Commercial. Salvage, piracy, and "finding" a hull do not register you. You can still fly a stolen ship if it has power, nav, RCS, and a transponder signal — but OGSIO knows the mismatch.
Expect these limits on a non-owned hull even after you install fresh gear:
Community reports on Steam are consistent: buying a cheap derelict, moving a nav console, and installing a freshly purchased transponder can change what scanners display, but the underlying hull remains unowned. Stolen transponders moved to a new frame can still read as stolen. Plan on either living with the flag or migrating modules onto a broker-purchased hull — covered in the ship building guide.
This is the ~5,200-search-volume question. The short answer: you buy the transponder for a ship you legally own, then install that hardware on whatever hull you actually fly. You cannot open the Transponder Broker tab until Ogiso recognizes at least one owned vessel.
Transponders are not generic commodities like crowbars. Each unit is keyed to a registration slot on a ship you paid for. That is why "how to buy a transponder for a stolen ship" always loops through "own something legal first" — the UI literally will not sell you the part otherwise.
The wiki-documented workaround: purchase a replacement transponder for Ship A (owned), remove any old XPDR on Ship B (stolen), install the new unit on Ship B, and power it. Scanners now see Ship A's registration while you sit in Ship B's cockpit. It works for flying and docking in many cases — but Ship B remains unowned. You still cannot sell it, still fight PASS quirks, and still see nav warnings on some builds.
If the nag screen and PASS limits cost more time than a salvage run earns, strip the stolen hull for parts — Polaris VDX-01 units, RCS pods, pumps — and rebuild inside a broker derelict. That path pairs with the salvage guide and money guide.
Separate search queries ask how to change a ship transponder name — that is registration data tied to the broker purchase, not a free-text field on the unit. You do not rename a transponder; you buy one keyed to an owned hull and optionally move the hardware. Hacking-style forgery is not in 1.0 — only the swap workflow above.
If you need to move a transponder after installation, uninstall it with the usual screwdriver or drill workflow, carry the unit through the ship, and remount on a wall with power conduit already routed. Cut power at the breaker first so ATC does not read half a move as a ghost signal.
Matched by build plan, shared topics, and guide progression — not random related links.
Transponders are ship systems, not passive cargo. They need electrical conduit from a powered bus — typically a ship battery or breaker panel output — and they fail silently when unplugged.
| Step | What to check |
|---|---|
| Mount point | Install on an interior wall or ceiling tile with clearance — treat like any other avionics box |
| Power port | Red/black conduit socket on the unit — match other ship systems; use PwrViz cartridge on PDA to confirm |
| Antenna link | Separate device; must also be powered and placed with exterior exposure per hull rules |
| Breaker isolation | Optional signal box or breaker panel lets you cut transponder power without killing the whole grid |
| Toggle UI | Interact with powered transponder to set ON/OFF — OFF saves power but changes ATC behavior |
The Renbao Portal PDA accepts a PwrViz cartridge that overlays power flow in AR. When Reddit and Steam threads mention "transponder electrical connection point," they usually mean "follow the conduit from the battery until the overlay shows the XPDR drawing load." If the unit reads OFF and cannot toggle, trace power first — not registration.
Running conduit through an unpowered breaker, forgetting the antenna entirely, or powering the transponder from a bus that browns out when RCS fires are the top three fixes. Route critical avionics through a dedicated battery bank if your fusion reactor dips output during startup.
Toggle state is a stealth-versus-legibility decision. ON broadcasts your registration (real or swapped). OFF stops the hail-friendly handshake — but absence of signal is its own tell in patrolled space.
| State | Typical effect |
|---|---|
| ON + valid reg | Normal dock clearance; PASS lists you; patrols treat you as paperwork-complete |
| ON + mismatched/stolen hull | May dock short-term but deeper scans still compare hull mass vs registry |
| OFF | Harder to ID at distance; local authority interest rises — "ghost ship" behavior |
| OFF + no antenna | Same as OFF but also fails minimum legal kit if you need to dock formally |
Wiki ship-ownership and faction pages stress: transponder state feeds local security scrutiny. Running dark near OKLG or Ceres trade lanes invites intercepts you might have avoided with a clean broadcast. Running open near pirate-heavy boneyard vectors advertises which registration to spoof next.
Common reasons: slipping out of a dock before debt collectors hail you, masking a stolen hull until you reach a private berth, or saving wattage on a dead-battery escape. Re-enable before you need ATC clearance — toggling mid-dock is slower than having it on approaching the station.
If the UI shows OFF and refuses ON, check power first, damage second, installation third. A ruined XPDR from salvage may need broker replacement even if the case looks intact.
Salvage tier lists and community EVA guides both flag the Polaris "VDX-01" IFF assembly at roughly $29,000 kiosk value — one of the highest single-item scores in early EVA. It is not a cheat code for ownership, but it is absolutely a cheat code for paying OKLG rent.
| Question | Answer |
|---|---|
| What is it? | Premium Polaris-brand transponder / IFF avionics module |
| Typical value | ~$29,000 at License Kiosk with salvage permit |
| Install on stolen hull? | Physically yes; legally still does not confer ownership |
| Strip or keep? | Strip for cash early career; keep one only if you need a spare on an owned hull |
Treat it like any high-value avionics: screwdriver or power drill on the mounting bolts, verify suit oxygen, and cart it through the airlock before the derelict drifts. Structure cutters are for hull, not for delicate IFF boxes — one sloppy torch swing turns $29k into scrap kiosk prices.
Selling a VDX-01 to the License Kiosk requires your salvage permit and rewards cash — it does not register the donor hull to your name. Players who install a VDX-01 on a stolen frame hoping for a "premium" legal ID still hit the same ownership wall.
Yes — if you plan to sell stripped gear legally. The License Kiosk at OKLG sells a Salvage Permit (salvage license) that unlocks high-value buy prices on components like transponders, nav chips, and fusion parts. Without it, you are functionally treated as a pirate selling hot goods.
Different terminals, same station complex. Broker handles hull ownership and replacement transponders; License Kiosk handles permits and purchases of salvaged equipment. Budget for the permit early in your first debt cycle — sitting on a VDX-01 you cannot legally sell is worse than never having found it.
Damaged or low-tier loot still sells at Scrap Kiosks without the permit, at trash rates. The salvage guide covers when to strip vs when to tow whole hulls.
Use this as a pre-flight checklist when leaving OKLG with a salvaged or swapped registration.
| Mistake | Fix |
|---|---|
| Buying transponder before owning any hull | Purchase cheapest derelict at Ship Broker first |
| Powered transponder, no antenna | Install and wire antenna — both required for legal kit |
| Expecting swap to equal ownership | Accept PASS/barter/sell limits; plan module migration |
| Selling VDX-01 without salvage permit | License Kiosk first — see OKLG License terminal |
| Transponder OFF near patrol lane | Toggle ON before entering ATC space or expect intercepts |
| Brownout during dock approach | Buffer avionics on a dedicated battery — see reactor guide |
| Torching avionics during strip | Use screwdriver drill on mounts; cutters for hull only |
Own any hull via the Ship Broker Kiosk at OKLG Azikiwe Commercial, open the Transponder Broker tab, buy a replacement XPDR for that registration, then install it (with an antenna) on the hull you fly. This does not grant full legal ownership on a stolen frame.
Only if you buy that derelict through the broker. Salvage-towed hulls remain unowned until purchased.
Roughly $29,000 at the License Kiosk with a salvage permit — one of the best early EVA scores.
No — it removes your friendly ID broadcast and often increases local security interest. It is a trade-off, not stealth cloaking.
On the unit power port — run conduit from a ship battery or breaker output. Use a PwrViz PDA cartridge to verify draw.
Yes, to sell high-value stripped components like IFF units at full price. Buy the permit at the License Kiosk.
The hull is not in OGSIO under your name. Swapped transponders change broadcasts, not registry ownership.
Wire the grid on the fusion reactor guide, strip smarter on the salvage guide, and expand the hull in ship building.
August 16, 2026
Matched by build plan, shared topics, and guide progression — not random related links.
